The purpose of this proposed Industry-Academic Partnerships for Development of Imaging Systems Application is to develop novel approaches for computer assisted ultrathin bronchoscopy (CAUB) for biopsying small peripheral lung nodules. These traditionally have been difficult to diagnose using standard flexible bronchoscopes. We conclude that recent technical developments, including: the introduction of ultrathin bronchoscopes; widespread availability of multidetector CT scanners capable of generating near isotropic imaging of the entire lung; and newly developed advanced image processing algorithms, including sophisticated methods for segmenting and skeletonizing airways and vessels as well as virtual endoscopy, combined have the potential to alter current clinical algorithms for diagnosing lung nodules. While to date attention has almost exclusively focused on the use of virtual bronchoscopy (VB) to evaluate only the central airways, in our opinion a more robust approach to identifying peripheral airways is needed to extend the range of image guided bronchoscopy. At the heart of this application is the development of automated-methods for obtaining virtual endoscopic pathways leading to small peripheral lung nodules, including the use of pulmonary arteries as surrogate markers for the location of peripheral bronchi in those cases in which bronchi cannot be identified adjacent to lesions even using high-resolution near-isotropic CT images. These automated techniques can then be coupled with ultrathin bronchoscopy allowing the routine diagnosis of pulmonary nodules previously considered inaccessible to routine flexible bronchoscopy. Specific Aim 1 will be to create automatic virtual endoscopic roadmaps from central airways to small computer generated peripheral lung nodules as a means to assess the feasibility of automated pathway planning and airway/arterial correspondence. Specific Aim 2 will address the potential clinical application of these techniques in a Pilot Project. It is anticipated that these results will allow ultrathin bronchoscopy to emerge as the initial procedure of choice for assessing peripheral lung nodules thus altering present clinical paradigms. [unreadable] [unreadable]